我想知道如何设置一个宽度,以匹配父布局宽度

new Container(
  width: 200.0,
  padding: const EdgeInsets.only(top: 16.0),
  child: new RaisedButton(
    child: new Text(
      "Submit",
      style: new TextStyle(
        color: Colors.white,
      )
    ),
    colorBrightness: Brightness.dark,
    onPressed: () {
      _loginAttempt(context);
    },
    color: Colors.blue,
  ),
),

我知道一点点关于扩展小部件,但扩展扩展视图到两个方向,我不知道如何做到这一点。


当前回答

您可以通过设置小部件的匹配父项

1)设置宽度为两倍。无穷:

new Container(
          width: double.infinity,
          padding: const EdgeInsets.only(top: 16.0),
          child: new RaisedButton(
            child: new Text(
                "Submit",
                style: new TextStyle(
                  color: Colors.white,
                )
            ),
            colorBrightness: Brightness.dark,
            onPressed: () {
              _loginAttempt(context);
            },
            color: Colors.blue,
          ),
        ),

2)使用MediaQuery:

new Container(
          width: MediaQuery.of(context).size.width,
          padding: const EdgeInsets.only(top: 16.0),
          child: new RaisedButton(
            child: new Text(
                "Submit",
                style: new TextStyle(
                  color: Colors.white,
                )
            ),
            colorBrightness: Brightness.dark,
            onPressed: () {
              _loginAttempt(context);
            },
            color: Colors.blue,
          ),
        ),

其他回答

经过一番研究,我找到了一些解决方案,感谢@Günter Zöchbauer,

我用了列而不是容器和

将属性设置为列CrossAxisAlignment。拉伸填充匹配按钮的父元素

    new Column(
              crossAxisAlignment: CrossAxisAlignment.stretch,
              children: <Widget>[
                new RaisedButton(
                  child: new Text(
                      "Submit",
                      style: new TextStyle(
                        color: Colors.white,
                      )
                  ),
                  colorBrightness: Brightness.dark,
                  onPressed: () {
                    _loginAttempt(context);
                  },
                  color: Colors.blue,
                ),
              ],
            ),

TRY

Flexible(
 child: Row(
  children: [
    ElevatedButton(
     onPressed: () {},
     child: Text("love you}"),
   ),
  ],
 ),
),

@Mohit Suthar,

找到了一个最好的解决方案,匹配父宽以及高度如下

new Expanded(
          child: new Container(
              padding: EdgeInsets.all(16.0),
              margin: EdgeInsets.all(16.0),
              decoration: new BoxDecoration(
                  color: Colors.white,
                  borderRadius:
                      const BorderRadius.all(const Radius.circular(8.0)),
                  border: new Border.all(color: Colors.black, width: 1.0)),
              child: new Text("TejaDroid")),
        ), 

在这里,您可以检查扩展控制器获得完整的宽度和高度。

您可以通过设置小部件的匹配父项

1)设置宽度为两倍。无穷:

new Container(
          width: double.infinity,
          padding: const EdgeInsets.only(top: 16.0),
          child: new RaisedButton(
            child: new Text(
                "Submit",
                style: new TextStyle(
                  color: Colors.white,
                )
            ),
            colorBrightness: Brightness.dark,
            onPressed: () {
              _loginAttempt(context);
            },
            color: Colors.blue,
          ),
        ),

2)使用MediaQuery:

new Container(
          width: MediaQuery.of(context).size.width,
          padding: const EdgeInsets.only(top: 16.0),
          child: new RaisedButton(
            child: new Text(
                "Submit",
                style: new TextStyle(
                  color: Colors.white,
                )
            ),
            colorBrightness: Brightness.dark,
            onPressed: () {
              _loginAttempt(context);
            },
            color: Colors.blue,
          ),
        ),

这对我很有用。

    SizedBox(
             width: double.maxFinite,
             child: RaisedButton(
                 materialTapTargetSize: MaterialTapTargetSize.shrinkWrap,
                 child: new Text("Button 2"),
                 color: Colors.lightBlueAccent,
                 onPressed: () => debugPrint("Button 2"),
              ),
     ),